Skip to content

Earlier editions: 20222019

Chapter 6 — WATER SUPPLY AND DISTRIBUTION

604.1 Pipe, Tube, and Fittings.

California Plumbing Code (Title 24, Part 5) · 2025 edition · updated 2026-09-10 · California

Italicized text is a California amendment to the model code, as printed in the official publication.

Pipe, tube, fittings, solvent cement, thread sealants, solders, and flux used in potable water systems intended to supply drinking water shall comply with NSF/ANSI/CAN 61. Where pipe fittings and valves are made from copper alloys containing more than 15 percent zinc by weight and are used in plastic piping systems, they shall be resistant to dezincification and stress corrosion cracking in compliance with NSF/ANSI 14.

Materials used in the water supply system, except valves and similar devices, shall be of a like material, except where otherwise approved by the Authority Having Jurisdiction.

Materials for building water piping and building supply piping shall comply with the applicable standards referenced in Table 604.1.

Exception: [OSHPD 1, 2, 3, 4 & 5] Use of CPVC is not per- mitted for potable water applications. 604.1.1 Local Authority to Approve CPVC Pipe Within Residential Buildings Under Specified Con- ditions. [HCD 1 & HCD 2] The local responsible build- ing official of any city, county, or city and county, shall authorize by permit the use of CPVC for hot and cold water distribution systems within the interior of residential build- ings provided all of the following conditions are satisfied:

(a) Permit Conditions. Any building permit issued pur- suant to Section 604.1.1 shall be conditioned on compliance with the mitigation measures set forth in this section.

(b) Approved Materials. Only CPVC plumbing mate- rial listed as an approved material and installed in accordance with this code may be used.

(c) Installation and Use. Any installation and use of CPVC plumbing material pursuant to this section shall comply with all applicable requirements of this code and the manufacturer’s installation instructions.

(d) Certification of Compliance. Prior to issuing a building permit pursuant to Section 604.1.1, the building official shall require as part of the permit- ting process that the contractor, or the appropriate plumbing subcontractors, provide written certifica- tion: (1) that is required in subdivision (e), and (2) that he or she will comply with the flushing proce- dures and worker safety measures of this code and the manufacturer’s installation instructions.

(e) Worker Safety. Any contractor applying for a build- ing permit that includes the use of CPVC plumbing materials authorized pursuant to this section shall include in the permit application a signed written certification stating that:

(1) They are aware of the health and safety hazards associated with CPVC plumbing installations;

(2) They have included in their Injury and Illness Prevention Plan the hazards associated with CPVC plumbing pipe installations; and

(3) The worker safety training elements of their Injury and Illness Prevention Plan meet the Department of Industrial Relation’s guidelines.

(f) Findings of Compliance. The building official shall not give final permit approval of any CPVC plumbing materials installed pursuant to Section 604.1.1 unless he or she finds that the material has been installed in compliance with the requirements of this code and the manufacturer’s installation instructions.

(g) Penalties. Any contractor or subcontractor found to have failed to comply with the flushing, ventilation, and glove requirements of this code and the manu- facturer’s installation instructions shall be subject to the penalties in Health and Safety Code, Division 13, Part 1.5, Chapter 6 (Section 17995 et seq.). In addition, if during the conduct of any building inspection the building official finds that the venti- lation and glove requirements of this code, are being violated, such building officials shall cite the con- tractor or subcontractor for that violation.

(h) Special Requirements for CPVC Installation within Residential Structures. In addition to the other requirements in the California Plumbing Code, all installations of CPVC pipe within resi- dential structures shall meet the following:

(i) Flushing Procedures. All installations of CPVC pipe within residential structures shall be flushed twice over a period of at least one (1) week. The pipe system shall be first flushed for at least 10 minutes and then filled and allowed to stand for no less than 1 week, after which all the branches of the pipe system must be flushed long enough to fully empty the con- tained volume. At the time of the fill, each fix- ture shall have a removable tag applied stating:

“This new plumbing system was first filled on (date) by (name). The California Department of Housing and Community Development requires that the sys- tem be flushed after standing at least one week after the fill date specified above. If the system is used ear- lier than one week after the fill date, the water must be allowed to run for at least two minutes prior to use for human consumption. This tag may not be removed prior to flushing, except by the homeowner.”

(ii) Worker Safety Measures. Mechanical ventila- tion sufficient to maintain exposures below the relevant exposure limits established by state regulation shall be provided in enclosed spaces. This ventilation shall be directed at the breath- ing zone of the worker installing the pipe. Where mechanical ventilation is not practical, respirators, suitable for organic vapors, shall be used. For the purpose of this subdivision, an enclosed space is defined as:

(1) A space less than 100 square feet of floor area under a ceiling with a height of 10 feet or less, and which does not have openings (consisting of doors, windows, or unfin- ished walls) on at least two sides;

(2) Crawl spaces having a height of less than three feet;

146 2025 CALIFORNIA PLUMBING CODE

WATER SUPPLY AND DISTRIBUTION

(3) Enclosed attics that have a roof and ceil- ing; or

(4) Trenches having a depth greater than 24 inches.

Installers of CPVC pipe within residential struc- tures shall use non-latex thin gauge (4 millime- ters) nitrile gloves, or other gloves providing an equivalent or better degree of protection during the installation of the CPVC plumbing system. Gloves shall be provided to all workers by the contractor, or plumbing subcontractor, and shall be replaced upon contamination by cements.

604.1.2 PEX. [HCD 1 & HCD 2] All installations of PEX pipe where it is the initial plumbing piping installed in new construction shall be flushed twice over a period of at least one week. The pipe system shall be first flushed for at least 10 minutes and then filled and allowed to stand for no less than 1 week, after which all the branches of the pipe system must be flushed long enough to fully empty the contained volume. This provision shall not apply to the installation of PEX pipe where it replaces an existing pipe system of any material.

(1) At the time of fill, each fixture shall have a remov- able tag applied stating:

(a) “This new plumbing system was first filled and _flushed on ______ (date) by ____________ (name). The State of California requires that the system be flushed after standing at least one week after the fill date specified above. If this system is used earlier than one week after the fill date, the water must be allowed to run for at least two minutes prior to use for human con- sumption. This tag may not be removed prior to the completion of the required second flushing, except by the building owner or occupant.”

(2) Prior to issuing a building permit to install PEX pipe, the building official shall require as part of the permitting process that the contractor, or the appro- priate plumbing subcontractors, provide written cer- tification that he or she will comply with the flushing procedures set forth in the code.

(3) The building official shall not give final permit approval of any PEX plumbing installation unless he or she finds that the material has been installed in compliance with the requirements of the code, includ- ing the requirements to flush and tag the systems.

(4) Any contractor or subcontractor found to have failed to comply with the PEX flushing requirements shall be subject to the penalties in Health and Safety Code, Division 13, Part 1.5, Chapter 6 (Section 17995, et seq.).

Get a plain-English answer with a citation back to this text.

Ask AI about this code
Contents — California Plumbing Code (Title 24, Part 5)
California Plumbing Code (Title 24, Part 5)
  1. Chapter 1 — GENERAL CODE PROVISIONS
  2. Chapter 2 — DEFINITIONS
  3. Chapter 3 — GENERAL REGULATIONS
  4. Chapter 4 — PLUMBING FIXTURES AND FIXTURE FITTINGS
  5. Chapter 5 — WATER HEATERS
  6. Chapter 6 — WATER SUPPLY AND DISTRIBUTION
    Overview
    1. 601.1 Applicability. This chapter shall govern the materials,
    2. 601.2 Water Supply and Flushing. Each plumbing fixture shall b…
    3. 601.3 Identification of a Potable and Nonpotable
    4. 601.4 Schools of Cosmetology and Cosmetological
    5. 601.5 Meat and Poultry Processing Plants. [AGR]
    6. 601.6 Collection Centers and Facilities. [AGR]
    7. 601.7 Renderers. [AGR] This area shall be provided with
    8. 601.8 Horse Meat and Pet Food Establishments. [AGR]
    9. 602.1 Prohibited Installation. No installation of potable
    10. 602.2 Cross-Contamination. No person shall make a connection o…
    11. 602.3 Backflow Prevention. No plumbing fixture, device,
    12. 602.4 Approval by Authority. No water piping supplied
    13. 603.1 General. Cross-connection control shall be provided
    14. 603.2 Approval of Devices or Assemblies. Before a
    15. 603.3 Backflow Prevention Devices, Assemblies, and
    16. 603.4 General Requirements. Assemblies shall comply
    17. 603.5 Specific Requirements. Specific requirements for
    18. 604.1 Pipe, Tube, and Fittings. Pipe, tube, fittings, solvent …
    19. 604.2 Lead Content. The maximum allowable lead content
    20. 604.3 Copper or Copper Alloy Tube. Copper or copper
    21. 604.4 Hard-Drawn Copper or Copper Alloy Tubing.
    22. 604.5 Flexible Connectors. Flexible water connectors
    23. 604.6 Cast-Iron Fittings. Cast-iron fittings up to and
    24. 604.7 Malleable Iron Fittings. Malleable iron water fittings s…
    25. 604.8 Previously Used Piping and Tubing. Piping and
    26. 604.9 Epoxy Coating. The epoxy coating used on existing, under…
    27. 604.10 Plastic Materials. Approved plastic materials shall
    28. 604.11 Solder. Solder shall comply with the requirements of
    29. 604.12 Flexible Corrugated Connectors. Flexible corrugated con…
    30. 604.13 Water Heater Connectors. Flexible metallic (copper and …
    31. 605.1 Copper or Copper Alloy Pipe, Tubing, and
    32. 605.2 CPVC Plastic Pipe and Joints. CPVC plastic pipe
    33. 605.3 CPVC/AL/CPVC Plastic Pipe and Joints. Chlorinated polyvi…
    34. 605.4 Ductile Iron Pipe and Joints. Ductile iron pipe
    35. 605.5 Galvanized Steel Pipe and Joints. Galvanized
    36. 605.6 PE Plastic Pipe/Tubing and Joints. PE plastic
    37. 605.7 PE-AL-PE Plastic Pipe/Tubing and Joints. PEAL-PE plastic…
    38. 605.8 PE-RT. Polyethylene of raised temperature (PE-RT)
    39. 605.9 PEX Plastic Tubing and Joints. PEX plastic tubing and fi…
    40. 605.10 PEX-AL-PEX Plastic Tubing and Joints. PEXAL-PEX plastic…
    41. 605.11 Polypropylene (PP) Piping and Joints. PP pipe
    42. 605.12 PVC Plastic Pipe and Joints. PVC plastic pipe
    43. 605.13 Stainless Steel Pipe and Joints. Joining methods for st…
    44. 605.14 Slip Joints. In water piping, slip joints shall be perm…
    45. 605.15 Dielectric Unions. Dielectric unions where installed
    46. 605.16 Joints Between Various Materials. Joints
    47. 606.1 General. Valves up to and including 2 inches (50
    48. 606.2 Fullway Valve. A fullway valve controlling outlets
    49. 606.3 Multidwelling Units. In multidwelling units, one or
    50. 606.4 Multiple Openings. Valves used to control two or
    51. 606.5 Control Valve. A control valve shall be installed
    52. 606.6 Accessible. Required shutoff or control valves shall
    53. 606.7 Multiple Fixtures. A single control valve shall be
    54. 606.8 [OSHPD 1, 1R, 2, 3, 4 & 5] Each riser or branch
    55. 606.9 Check Valve Required. All systems that circulate
    56. 606.10 Leak Detection Devices. Where leak detection
    57. 607.1 General. Potable water supply tanks shall be installed in
    58. 607.2 Private Well Water Tanks. Pressurized potable water
    59. 607.3 Potable Water Tanks. Potable water supply tanks,
    60. 607.4 Venting. Tanks used for potable water shall be tightly
    61. 607.5 Overflow. Tanks shall have not less than a 16 square
    62. 607.6 Valves. Pressurized tanks shall be provided with a listed
    63. 608.1 Inadequate Water Pressure. Where the water pressure in t…
    64. 608.2 Excessive Water Pressure. Where static water
    65. 608.3 Expansion Tanks, and Combination Tempera-
    66. 608.4 Pressure Relief Valves. Each pressure relief valve
    67. 608.5 Discharge Piping. The discharge piping serving a
    68. 608.6 Water-Heating Devices. A water-heating device
    69. 608.7 Vacuum Relief Valves. Where a hot-water storage
    70. 609.1 Installation. Water piping shall be adequately supported…
    71. 609.2 Trenches. Water pipes shall not be run or laid in the
    72. 609.3 Under Concrete Slab. Water piping installed within
    73. 609.4 Testing. Upon completion of a section or of the entire
    74. 609.5 Unions. Unions shall be installed in the water supply
    75. 609.6 Location. Except as provided in Section 609.7, no
    76. 609.7 Abutting Lot. Nothing contained in this code shall
    77. 609.8 Pumps. Pumps shall be installed in accordance with
    78. 609.9 Low-Pressure Cutoff Required on Booster
    79. 609.10 Disinfection of Potable Water System. New or
    80. 609.11 Water Hammer. [Not adopted by HCD] Building
    81. 609.12 Pipe Insulation. Insulation of domestic hot water
    82. 610.1 Size. The size of each water meter and each potable
    83. 610.2 Pressure Loss. Where a water filter, water softener,
    84. 610.3 Quantity of Water. The quantity of water required to be
    85. 610.4 Sizing Water Supply and Distribution Systems.
    86. 610.5 Sizing per Appendices A, C, and M . Except as
    87. 610.6 Friction and Pressure Loss. Except where the type
    88. 610.7 Conditions for Using Table 610.4. On a proposed
    89. 610.8 Size of Meter and Building Supply Pipe Using
    90. 610.9 Size of Branches. Where Table 610.4 is used, the minimum…
    91. 610.10 Sizing for Flushometer Valves. Where using
    92. 610.11 Sizing Systems for Flushometer Tanks. The size
    93. 610.12 Sizing for Velocity. Water piping systems shall not
    94. 610.13 Exceptions. The provisions of this section relative
    95. 611.1 Application. Drinking water treatment units shall
    96. 611.2 Air Gap Discharge. Discharge from drinking water
    97. 611.3 Connection Tubing. The tubing to and from drinking water…
    98. 611.4 Sizing of Residential Softeners. Residential-use
    99. 612.1 Installation. Residential Sprinkler Systems shall be
    100. 613.1 The domestic water-heating equipment and distribu-
    101. 613.2 At least two pieces of hot-water-heating equipment shall
    102. 613.3 Instantaneous heaters are permitted for supplying hot
    103. 613.4 Water storage tanks shall be fabricated of corrosion-
    104. 613.5 Temperature control valves shall be provided to auto-
    105. 613.6 Hot-water distribution system serving patient care areas
    106. 613.7 At fixtures where water exceeding 125°F (52°C) is acces-
    107. 613.8 Sectionalizing valves shall be provided as required by
    108. 613.9 Hot water distribution shall include test ports and valved
    109. 614.1 Dialysis water feedlines shall be CPVC (chlorinated
    110. 614.2 All piping for multistation or central dialysis units sh…
    111. 614.3 All valves shall be located in accessible locations.
    112. 614.4 Piping and valves shall be identified according to their
    113. 614.5 A means of preventing backwashing or flushing of the
    114. 614.6 A continuous audible alarm shall sound at the nurses’
    115. 614.7 Water treatment equipment and water used for dialysis
    116. 614.8 A diagram of all piping as installed shall be posted at …
    117. 615.1 Uses Not Permitted.
    118. 615.2 [OSHPD 1, 1R, 2, 3, 4 & 5] Non-potable water sys-
    119. 615.3 [OSHPD 1, 1R, 2, 3, 4 & 5] Outlets for non-potable
    120. 616.1 For new acute care hospital buildings submitted after
    121. 616.2 The emergency supply of water shall be provided at ade-
    122. 616.3 Storage tank connections and circulation shall be
  7. Chapter 7 — SANITARY DRAINAGE
  8. Chapter 8 — INDIRECT WASTES
  9. Chapter 9 — VENTS
  10. Chapter 10 — TRAPS AND INTERCEPTORS
  11. Chapter 11 — STORM DRAINAGE
  12. Chapter 12 — FUEL GAS PIPING
  13. Chapter 13 — HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICA…
  14. Chapter 14 — FIRESTOP PROTECTION
  15. Chapter 15 — ALTERNATE WATER SOURCES FOR NONPOTABLE APPLICATIONS
  16. Chapter 16 — NONPOTABLE RAINWATER CATCHMENT SYSTEMS
  17. Chapter 17 — REFERENCED STANDARDS
  18. Appendix A — RECOMMENDED RULES FOR SIZING THE WATER SUPPLY SYS…
  19. Appendix B — EXPLANATORY NOTES ON COMBINATION WASTE AND VENT S…
  20. Appendix C — ALTERNATE PLUMBING SYSTEMS
  21. Appendix D — SIZING STORM WATER DRAINAGE SYSTEMS
  22. Appendix E — MANUFACTURED/MOBILE HOME PARKS AND RECREATIONAL V…
  23. Appendix F — FIREFIGHTER BREATHING AIR REPLENISHMENT SYSTEMS
  24. Appendix G — SIZING OF VENTING SYSTEMS
  25. Appendix H — PRIVATE SEWAGE DISPOSAL SYSTEMS
  26. Appendix I — INSTALLATION STANDARDS
  27. Appendix J — COMBINATION OF INDOOR AND OUTDOOR COMBUSTION AND …
  28. Appendix K — POTABLE RAINWATER CATCHMENT SYSTEMS
  29. Appendix L — SUSTAINABLE PRACTICES
  30. Appendix M — PEAK WATER DEMAND CALCULATOR
  31. Appendix N — IMPACT OF WATER TEMPERATURE ON THE POTENTIAL FOR …
  32. Appendix O — NON-SEWERED SANITATION SYSTEMS
  33. Appendix P — PROFESSIONAL QUALIFICATIONS
  34. Appendix Q — INDOOR HORTICULTURAL FACILITIES
  35. Appendix R — TINY HOUSES
  36. Appendix S — ONSITE STORMWATER TREATMENT SYSTEMS

GoCodebook provides public access, search, citation, multilingual explanation, and practical interpretation of legally adopted building regulations. It is not a substitute for the official ICC or California code publications.